Interface connector handle for disposable guidewire optical connection

ABSTRACT

The present document describes an interface connector handle for connecting a first optical fiber to a second optical fiber. The first optical fiber is substantially centered within a proximal portion of a guidewire tubing. The second optical fiber is routed through and extending from an optical interface cable. The interface connector handle comprises a biasing assembly for urging one of the first optical fiber and the second optical fiber toward the other one of the first optical fiber and the second optical fiber resulting in a contact therebetween.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/598,596 filed Aug. 29, 2012, which claims priority from U.S. patentapplication 61/529,029 filed Aug. 30, 2011, the specification of whichis hereby incorporated herein by reference in its entirety.

FIELD

The subject matter disclosed generally relates to guidewires forminimally invasive medical use. More specifically, it relates to methodsand devices for terminating optical fibers within guidewires.

BACKGROUND

The use of pressure measurement guidewires has been in existence for atleast the last 10 years. These pressure guidewires are most commonlyused to measure the pressure distal to a lesion (stenosis), mostcommonly in the coronary vasculature. By calculating the ratio betweenthe measured pressure distal to the lesion and some point more proximal,most commonly in the ascending aorta or the coronary tree root, thefractional flow reserve (FFR) is obtained. The FFR is now commonly usedto assess the significance of lesion stenosis and thereby to inform thephysician as to the most appropriate treatment strategy.

Current devices use piezo-electric pressure transducing elements mountedinto a guidewire for measuring blood pressure distal to stenosis thatintervene in the calculation of the FFR value. Piezo-electrictransducers however suffer from lack of stability as a result ofmoisture induced sensor drift. Optical pressure element as described inU.S. Pat. No. 7,689,071 do not suffer from such adverse effect and theyare better suited for FFR measurement such as for pressure guidewiredescribed in U.S. patent application Ser. No. 13/389,319.

Pressure guidewires also must allow easy disconnection and reconnectionof the guidewire to a pressure analyzer. Pressure guidewires involve themeasurement of distal blood pressure, followed by the insertion of otherinterventional medical devices such as Percutaneous TransluminalCoronary Angioplasty (PTCA) balloon catheter over the guidewire forstenting in case of significant lesion. It is however desirable to havethe ability to reliably re-connect the guidewire to the pressureanalyzer for post stenting FFR assessment, or for multi-vessel lesionassessment. Current electrical connectors such as those described inU.S. Pat. Nos. 4,958,642, 4,961,433, 5,178,159, 5,240,437, 5,358,409,5,348,481, 5,413,508, 6,196,980, 6,428,336, 7,274,956 are suited forelectrical connection. Although they have the ability to provide areliable electrical connection in dry conditions, they are typicallyquite sensitive to conditions where the surface of the guidewireconnector contacts are contaminated with blood residues after theremoval of the interventional device such as PTCA balloon catheter.

A selection of prior art documents is described below. They arediscussed for illustrative purposes only. These documents do notnecessarily represent the closest prior art.

U.S. Pat. No. 5,125,058 provides a method for optically connecting aguidewire mounted device to a relaying cable. The method however relieson the accuracy of the internal diameter of the guidewire, which isdifficult to achieve. The guidewire mounted optical fiber interface isrecessed within the guidewire, making the fiber surface polishing adifficult task. The optical portion that is devoted to be inserted intothe guidewire needs to be of very small diameter, making the connectorvery sensitive to mechanical damage.

U.S. Pat. No. 5,601,087 relies on the addition to the guidewire shaft ofa proximal tubing portion, often called ferrule, with accurate outsidediameter for alignment purpose. The addition of such proximal tubingportion adds extra production steps to the device and represents achallenging assembly process considering the presence of optical parts.

U.S. Pat. No. 6,445,939 also relies on the addition of a ferruleattached to the proximal end of the guidewire shaft. It is indeed verydifficult and expensive to machine such a tinny precise ferrule, and toattach it to the proximal end of the guidewire shaft.

U.S. Pat. No. 7,736,301 also relies on the addition of a ferrule nearthe proximal end of the guidewire shaft. The ferrule is, in this case,not attached to the guidewire as it is desired to allow for rotationalconnection, hence further increasing the requirement on the diametertolerance of the parts.

Hence, there is a need for an optical guidewire connector having theability to reliably connect a guidewire mounted optical pressure sensorto an external pressure analyzer or a similar opto-electronic device;that is disposable, and hence that is easy to produce and is low in costof material; and that is not sensitive to the presence of moisture orblood contamination.

SUMMARY

According to an embodiment, there is described a method for terminatinga first optical fiber within a proximal portion of a guidewire tubing.The guidewire tubing has an outside diameter defined as having atolerance of 0.001″ or better. The method comprises centering the firstoptical fiber within the guidewire tubing.

According to an aspect, the method further comprises grinding,polishing, or etching the guidewire tubing to bring the outside diameterwithin a tolerance of ±0.001″ or better.

According to an aspect, a gap exists between an outside diameter of thefirst optical fiber and an inside diameter of the guidewire tubing, themethod further comprising slipping an overlay tubing over the opticalfiber to fill the gap at least in part.

According to an aspect, the centering comprises centering the firstoptical fiber relative to the outside diameter of the guidewire tubingusing an alignment centering tubing device, the method furthercomprising using an adhesive for securing the first optical fiber in thecenter of guidewire proximal portion.

According to an aspect, the alignment centering tubing device comprisesa first ferrule having an inside diameter adapted to the outsidediameter of the guidewire tubing, a second ferrule having an insidediameter adapted to an outside diameter of the first optical fiber, themethod further comprising concentrically aligning the first ferrule andthe second ferrule.

According to an aspect, the aligning the first ferrule and secondferrule comprises using a split sleeve over the first ferrule and secondferrule thereby holding both ferrules coaxially.

According to an aspect, a gap exists between an outside diameter of thefirst optical fiber and an inside diameter of the guidewire tubing, andwherein the centering further comprising slipping an overlay tubing overthe optical fiber to fill the gap at least in part.

According to an aspect, the alignment centering tubing device comprisesa first ferrule having an inside diameter adapted to the outsidediameter of the guidewire tubing, a second ferrule having an insidediameter adapted to an outside diameter of an overlay tubing, the methodfurther comprising concentrically aligning the first ferrule and thesecond ferrule.

According to another embodiment, there is described a method forconnecting a first optical fiber within a proximal portion of aguidewire tubing, the method comprising: centering the first opticalfiber within the proximal portion of the guidewire tubing; andconnecting the first optical fiber to a female connector comprising asecond optical fiber having a core diameter different from a corediameter of the first optical fiber.

According to an aspect, the method further comprises connecting thefirst optical fiber to a female connector comprising an alignmentcentering tubing device comprising a first ferrule having an insidediameter adapted to the outside diameter of the guidewire tubing, asecond ferrule having an inside diameter adapted to an outside diameterof a second optical fiber for relaying an optical signal to an externalsignal conditioner unit, the method further comprising concentricallyaligning the first ferrule and the second ferrule.

According to an aspect, the first ferrule and second ferrule are alignedwith a split sleeve holding both ferrules coaxially.

According to another embodiment, there is described a female opticalreceiving device for connecting a first optical fiber to a secondoptical fiber, the first optical fiber being substantially centeredwithin a proximal portion of a guidewire tubing, the female opticalreceiving device comprising a first ferrule having a longitudinal axisand an inside diameter adapted to an outside diameter of the guidewiretubing, a second ferrule having a longitudinal axis and an insidediameter adapted to an outside diameter of the second optical fiber, thelongitudinal axis of the first ferrule being aligned with thelongitudinal axis of the second ferrule.

According to an aspect, the device further comprises a split sleeveslipped and fixed over the first ferrule and the second ferrulesimultaneously thereby aligning the longitudinal axis of the firstferrule and the longitudinal axis of the second ferrule.

According to an aspect, the second optical fiber has a core diameterdifferent from a core diameter of the first optical fiber, the secondoptical fiber being fixed within the second ferrule.

According to another embodiment, there is described, an interfaceconnector handle for connecting a first optical fiber to a secondoptical fiber, the first optical fiber being substantially centeredwithin a proximal portion of a guidewire tubing, the second opticalfiber being routed through and extending from an optical interfacecable, the interface connector handle comprising a biasing assembly forurging the first optical fiber into contact with the second opticalfiber.

According to an aspect, the handle further comprises a female opticalreceiving device at a distal end of the second optical fiber and whereinfirst optical fiber is for insertion in the female optical receivingdevice in order to contact the second optical fiber.

According to an aspect, the biasing assembly comprises a collet throughwhich the guidewire tubing is pushed and held in place when the colletis in a closed position.

According to an aspect, the biasing assembly further comprises a biasingdevice and a connector cap through which the guidewire tubing is slidtoward the female optical receiving device, the connector cap capable ofmovement in a direction, the biasing device exercising a counter forceopposite the direction of movement of the connector cap, the counterforce forcing the collet toward the closed position.

According to another embodiment, there is described a method forterminating a first optical fiber within a proximal portion of aguidewire tubing, the method comprising centering the first opticalfiber relative to the outside diameter of the guidewire tubing using analignment centering tubing device, the method further comprising usingan adhesive for securing the first optical fiber in the center ofguidewire proximal portion.

According to an aspect, the alignment centering tubing device comprisesa first ferrule having an inside diameter adapted to the outsidediameter of the guidewire tubing, a second ferrule having an insidediameter adapted to an outside diameter of the first optical fiber, themethod further comprising concentrically aligning the first ferrule andthe second ferrule.

According to an aspect, the aligning the first ferrule and secondferrule comprises using a split sleeve over the first ferrule and secondferrule thereby holding both ferrules coaxially.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention are incorporated and constitute a part ofthis specification, illustrate an exemplary embodiment of the inventionthat together with the description serve to explain the principles ofthe invention.

FIG. 1 is a schematic diagram of the guidewire assembly connectionshowing a cross-section of an interface cable handle according to anembodiment;

FIG. 2 is a schematic diagram showing a cross-section of the proximalend of the guidewire with its optical fiber protruding therefromaccording to an embodiment;

FIG. 3 is schematic diagram showing a cross-section of an alignmentassembly device for aligning the optical fiber in the center of theproximal end of guidewire according to an embodiment;

FIG. 4 is schematic diagram showing a cross-section of guidewireproximal end terminated to provide connectivity according to anembodiment;

FIG. 5 is a schematic diagram showing a cross-section of guidewireproximal end terminated to provide connectivity according to anotherembodiment that comprises an overlay tubing;

FIGS. 6A and 6B are schematic diagrams showing cross-sections of analignment assembly device for aligning the optical fiber with overlaytubing in the center of the proximal end of guidewire according toanother embodiment;

FIGS. 7A and 7B are schematic diagrams showing cross-sections of anoptical female connectivity part used to receive a guidewire proximalend and aligning respective fibers together according to an embodiment;

FIG. 8 is a schematic diagram showing a cross-section view of a handlewhich can be used in a method for holding female receiving optical partsat the end of an optical interface cable according to an embodiment;

FIG. 9 is a schematic diagram showing a side view of the handle of FIG.8; and

FIGS. 10A and 10B are schematic diagrams showing a cross-section view ofthe handle of FIG. 8 in the open position (FIG. 10A) and the closedposition (FIG. 10B).

DETAILED DESCRIPTION

In the following description of the embodiments, references toaccompanying drawings are by way of illustration of an example by whichthe invention may be practised. It will be understood that otherembodiments may be made without departing from the scope of theinvention disclosed.

The system 2 for measuring FFR is shown in FIG. 1. It comprises aguidewire 1 instrumented with an optical pressure sensor 7 near thedistal end (toward the patient). The guidewire 1 is therefore built witha hollow tubing (i.e., a guidewire tubing) for accommodating the opticalfiber (not shown). The guidewire proximal end (toward the clinician) isterminated with a connectivity end for connecting to optical interfacecable 5. The optical interface cable 5 is used to relay the opticalsignal from signal conditioner unit 3 (e.g., an optical analyzer) toguidewire mounted optical pressure sensor 7, and back to signalconditioner unit 3. Guidewire 1 comprises an internal optical fiber (notshown) that carries the light signal to the optical pressure sensor 7and back to signal conditioner unit 3. In this respect, both opticalfiber in the guidewire 1 and the optical fiber in the optical interfacecable 5 need to be coaxially aligned and held in contact during use. Thedistal end of the optical interface cable 5 is terminated with opticalalignment device 6 (also referred to herein as the female opticalreceiving device) that is embedded within the interface cable handle 4.

FIG. 2 shows a first embodiment of the proximal portion 10 of theguidewire 1 such that after some further processing as detailed withreference to FIG. 3 herein below, it can be connectorized to an opticalinterface cable 5 (see FIG. 7A). Guidewire proximal portion outerdiameter 13 of the guidewire 1 has an accurate and precise diameter.

The first optical fiber 11 can be aligned in the center of the guidewiretubing 12 with a positioning apparatus having the ability tomechanically position the first optical fiber 11 in the center of theguidewire 1, i.e., concentric with the end of the guidewire proximalportion 10. The position of the first optical fiber 11 relative to theguidewire tubing 12 is measured by methods such as those available fromBeta LaserMike, Dayton, Ohio.

The optical fiber alignment method shown in FIG. 3 is a preferred methodbecause its compactness does not require a high level of mechanicalstability for the assembly apparatus, while also being a self-alignmentmethod. The alignment assembly device 20 (also known as an alignmentcentering tubing device) is made of a first alignment ferrule 21, tubingor similar device having a precise internal diameter 22 adapted toreceive the guidewire proximal portion 10. By way of example, the firstalignment ferrule 21 is preferably made with a commercial optical fiberalignment ferrule, either made of ceramic, zirconium, glass, stainlesssteel or other material providing adequate support and alignmentaccuracy. In the following, it is understood that ferrule is either aferrule, a tubing or other similar device made of ceramic, zirconium,glass, stainless steel or other adequate material. Commercial ferrulesfor optical fibers are made with tolerances on eccentricity and holediameter of the order of ±1 micron. A preferred outside diameter of suchferrules is typically of 1.25 mm, although it can be of other diameterssuch as 2.5 mm. The second alignment ferrule 23 is used to receive thefirst optical fiber 11 and it is therefore selected to have an internaldiameter 24 that matches the diameter of the optical fiber cladding.Both ferrules are then coaxially aligned with the use of a split sleeve25.

Proper centering of the first optical fiber 11 within the guidewireproximal portion 10 is therefore possible considering the guidewireproximal portion outer diameter 13 is accurate. The guidewire proximalportion 10 shall have an guidewire proximal portion outer diameter 13with a tolerance better than ±0.001″, and preferably it shall have atolerance better than ±0.0005″. One preferred method of obtaining adiameter with an accuracy of ±0.0005″ or better is to grind theguidewire proximal portion 10 of the guidewire tubing 12 outer surfaceusing a center-less grinder or other types of grinders known by thoseskilled in the art to be appropriate for this task. It is also obviousfor those skilled in the art that other methods such as electro-etchingcan be used for the same purpose. The first optical fiber 11 is thenaligned in the axial center of the guidewire tubing 12, and fixed inplace using an adhesive 14.

Alignment assembly device 20 shown in FIG. 3 is therefore used to centerthe first optical fiber 11 in the guidewire tubing 12. The opticalguidewire is prepared by letting the first optical fiber 11 protrude outof the guidewire tubing 12. The required amount of adhesive 14 is thenprovided to fill the gap between the first optical fiber 11 and theinternal surface 26 of the guidewire proximal portion 10, and leftuncured. The guidewire proximal portion 10 with protruding first opticalfiber 11 is then inserted into the first alignment ferrule 21 and pushedsuch that the first optical fiber 11 enters into the second alignmentferrule 23. Depending on specific alignment assembly device 20, theguidewire proximal portion 10 can be pushed close to or in intimatecontact with the second alignment ferrule 23, hence minimizing opticalfiber misalignment that may be caused by the first optical fiber 11bending outside second alignment ferrule 23. The adhesive 14 is thencured according to known adhesive curing methods.

An alternative method consists in inserting the guidewire proximalportion 10 within the first alignment ferrule 21 and pushed such thatthe first optical fiber 11 enters into the second alignment ferrule 23with no adhesive yet. The required amount of adhesive 14 for filling thegap between the first optical fiber 11 and the internal surface 26 ofthe guidewire proximal portion 10 is then provided, followed by a curingstep of the adhesive 14. This alternative method helps in preventing theadhesive 14 from also filling the gap between the guidewire proximalportion 10 and the internal surface of the first alignment ferrule 21,allowing an easy removal of the guidewire assembly after the adhesive 14is cured.

Once the adhesive 14 is cured, the guidewire with centered first opticalfiber 11 is retrieved from the alignment assembly device 20 to beterminated as shown in FIG. 4. The guidewire optical termination surface31 of the guidewire is polished such that the first optical fiber 11 canbe connected to the interface cable optical fiber (not shown here).Although the guidewire optical termination surface 31 can be polished ona hard surface, it is preferred to polish the guidewire proximal portion10 on a soft polishing surface such that the optical fiber terminationis provided with the ability to form a physical contact with theinterface cable optical fiber.

The optical connectorization method shown in FIG. 4 is however notoptimal. The relatively large amount of adhesive 14 used to fill the gap32 between the first optical fiber 11 and the internal diameter of theguidewire tubing 12 makes such optical connection susceptible to opticalfiber misalignment during assembly and over time. As the amount ofadhesive 14 increases during assembly, the risk of having the adhesive14 unevenly distributed increases, which in turn increases the risks ofunevenly pulling the first optical fiber 11 off the axial center. Inuse, all adhesives have the tendency to swell over time, especially whenin presence of moisture and with temperature change. A relatively largeamount of adhesive 14 therefore makes the optical termination moreunstable.

The termination shown in FIG. 5 is a variation of the one shown in FIG.4, where the gap between the first optical fiber 11 and the internalsurface 26 of the guidewire proximal portion 10 is partially filled withan overlay tubing 36. In an embodiment, the overlay tubing 36 isselected to precisely match the first optical fiber 11. The amount ofadhesive 14 holding the fiber in the center of the guidewire proximalportion 10 is significantly reduced, hence long term stability of theoptical connection is assured.

The optical connection illustrated in FIG. 5 can be terminated using thesame optical assembly device shown in FIG. 3. The overlay tubing 36 inthis case would just barely extend further than the guidewire proximalportion 10 during assembly.

For those cases where the overlay tubing 36 is very precise, it mayhowever be desirable to use the alignment assembly device 27 shown inFIG. 6A, where the second alignment ferrule 41 has an internal diameteradapted to receive the overlay tubing 36. However, misalignment errorscaused by tolerances of inner diameter 37 and outer diameter 38 of theoverlay tubing 36 add up to the final coaxial positioning error of thefirst optical fiber 11, potentially leading to sub-optimalconcentricity. It has been found that the optical fiber providesadequate stiffness for aligning concentrically with the guidewire whenaligned with set-up and alignment method shown in FIG. 3. A preferredmethod consists in using an overlay tubing that does not precisely fitover the first optical fiber 11.

FIG. 6B illustrates such a preferred assembly method and alignmentassembly device 20 using an overlay tube 39 that does not precisely fitover the first optical fiber 11. The concentric alignment of the firstoptical fiber 11 within the guidewire proximal portion 10 is assured byinserting the first optical fiber 11 in a second alignment ferrule 23having an internal diameter matching the outside diameter of the firstoptical fiber 11, while the overlay tube 39 purpose is mainly forfilling the gap 32 (shown in FIG. 4).

The above embodiments describe various methods and devices for making anoptical connection at the proximal end of an optical guidewire. There ishowever also a need for a female part receiving the guidewire opticalconnection to provide an optical connection with the optical interfacecable 5 for relaying the optical signal to a signal conditioner unit 3(see FIG. 1).

FIGS. 7A and 7B show the optical parts used to construct such a femaleoptical receiving device 6. The female optical receiving device 6 isbuilt in a way very similar to the alignment assembly device 20 shown inFIG. 3. The first ferrule 51 herein is also used to receive theguidewire 1, with the inner diameter 52 adapted to receive the guidewireproximal portion 10. First ferrule 51 and second ferrule 53 are alignedand held together using split sleeve 54. The second ferrule 53 ishowever selected to receive the second optical fiber 55 routed throughthe optical interface cable 5 (see FIGS. 1 and 8). By way of an example,the optical interface cable 5 comprises the second optical fiber 55having a core diameter of 62.5 μm and a cladding diameter of 125 μm. Inthis case, the second ferrule 53 is selected with a diameter of 126 μmor 127 μm. The second optical fiber 55 is bonded inside the secondferrule 53 and polished so as to provide an adequate optical surface 56compatible with the guidewire optical termination.

FIG. 7B shows the female optical receiving device 6 with the guidewireproximal portion 10 engaged within the first ferrule 51. The opticalconnection will take place with minimal losses provided that the firstoptical fiber 11 is coaxially aligned with the second optical fiber 55,and provided that the faces of both first optical fiber 11 and secondoptical fiber 55 are in intimate contact.

FIG. 8 shows an interface connector handle 4 which can be used in amethod for holding the female optical receiving device 6. A secondoptical fiber 55 is connected to the female optical receiving device 6on one side, and runs through the optical interface cable 5 on the otherside. The female optical receiving device 6 is held in the center of theinterface connector handle 4 and pushed against a surface 68 with thehelp of a spring 67. The guidewire proximal portion 10 (see FIG. 7B) isinserted through the conical entrance 66 of the connector cap 61, it ispushed through the collet 63 then inside the female optical receivingdevice 6 such that the guidewire optical termination surface 31 (seeFIG. 4) and the optical surface 56 (see FIG. 7A) of the second opticalfiber 55 are in contact. The user can then tighten the connector cap 61.Connector cap proximal end 62 therefore pushes on collet 63 whichresults in closing such collet 63 by counter force exerted by spring 65through seat 70. It is understood that spring 65 can be replaced bysimilar device such as rubber tube or other biasing device. The actionof pushing the tightening collet 63 into seat 70 has the effect ofclosing the tightening collet 63 onto the guidewire proximal portion 10,firmly holding it in place.

According to an embodiment, the interface connector handle 4 comprises abiasing assembly (not number) for urging the first optical fiber 11 intocontact with the second optical fiber 55. The biasing assembly maycomprise collet 63 through which the guidewire 1 is pushed and held inplace when the collet 63 is in a closed position. The biasing assemblymay further comprise a biasing device (spring 65) and connector capthrough which the guidewire tubing is slid toward the female opticalreceiving device, the connector cap 61 capable of movement in adirection. The biasing device exercises a counter force opposite thedirection of movement of the connector cap 61 and the counter forceforces the collet 63 toward the closed position.

One aspect of the method using interface connector handle 4 is to assureand maintain a good physical contact between both the optical interfaceof guidewire 1 and the optical interface of female optical receivingdevice 6. Physical contact is assured by the displacement of theguidewire proximal portion 10 provided upon tightening the connector cap61. Upon tightening connector cap 61, collet 63 first closes and gripsthe guidewire proximal portion 10, forcing guidewire optical terminationsurface 31 (see FIG. 4) to push against the optical surface 56 of thesecond optical fiber 55 (see FIG. 7A). This action is illustrated inFIGS. 10A and 10B.

FIG. 10A shows the connector handle in an open position and FIG. 10Bshows the connector handle in a closed (downward) position, where onecan see the downward position in FIG. 10B of both the collet 63 and thefemale optical receiving device 6. The downward displacement ofguidewire 1 pushing against female optical receiving device 6 isprovided by the pitch of the sliding rail 72 and its interaction withprotrusion 71 (see FIG. 9). The downward displacement of the guidewire 1against the female optical receiving device 6 translates into contactingpressure between both optical termination interfaces (guidewire opticaltermination surface 31 (see FIG. 4) and the optical surface 56 of thesecond optical fiber 55 (see FIG. 7A). The force is provided by thespring 67 that is pushing against female optical receiving device 6. Thespring 67, applies its pressure on the female optical receiving device 6through a flange 69 that is mounted on the second ferrule 53 (see FIG.7A). The pressure between the optical interfaces assures a good physicalcontact and therefore a good optical connection.

The above method of exerting a mutual pressure on the opticaltermination surfaces of both a guidewire and an optical receiving deviceis described by way of an example. Other methods of imposing a relativemovement between the guidewire and the optical receiving device areunderstood to be within the scope of the present description. Forexample, there may exist a method for moving the internal receivingdevice apart from the guidewire prior to guidewire insertion, followedby a release after the guidewire is tightened within a connector handle.

The quality of the optical connection is related to the relativecentering of both optical fiber axis where they interface. One methodfor reducing the tolerance on this centering is to use a second opticalfiber 55 in the optical interface cable 5 with a core diameter differentfrom the core diameter of the optical fiber (not shown) of the guidewire1. Although this approach is not always possible, there are opticalmeasuring methods that are well suited for such a strategy. Forinstance, the pressure sensor described in U.S. Pat. No. 7,689,071 andassociated signal conditioning unit described in U.S. Pat. No. 7,259,862are well suited for the implementation of such a strategy.

While preferred embodiments have been described above and illustrated inthe accompanying drawings, it will be evident to those skilled in theart that modifications may be made without departing from thisdisclosure. Such modifications are considered as possible variantscomprised in the scope of the disclosure.

The invention claimed is:
 1. An interface connector handle forconnecting a first optical fiber to a second optical fiber, the firstoptical fiber being bonded within a proximal portion of a guidewiretubing, the guidewire being disconnectable from the interface connectorhandle, the second optical fiber being routed through and extending froman optical interface cable, the interface connector handle comprising: abiasing assembly which causes a relative movement between the firstoptical fiber and the second optical fiber to provide a contacttherebetween.
 2. The interface connector handle of claim 1, furthercomprising a female optical receiving device at a distal end of thesecond optical fiber and wherein the first optical fiber is forinsertion in the female optical receiving device in order to contact thesecond optical fiber.
 3. The interface connector handle of claim 2,wherein the biasing assembly comprises a biasing device for urging thefemale optical receiving device toward the proximal portion of theguidewire tubing.
 4. The interface connector handle of claim 3, whereinthe biasing device comprises a spring.
 5. The interface connector handleof claim 4, wherein the biasing assembly further comprises a flangemounted on the female optical receiving device and adjacent to thespring, the spring being for urging, through the flange, the femaleoptical receiving device toward the proximal portion of the guidewiretubing.
 6. The interface connector handle of claim 3, wherein thebiasing assembly for urging the female optical receiving device towardthe proximal portion of the guidewire tubing comprises a biasingassembly for exerting a mutual pressure between the first and the secondoptical fibers, wherein the first optical fiber is substantiallycentered within the proximal portion of the guidewire tubing.
 7. Theinterface connector handle of claim 1, wherein the biasing assemblycomprises a collet through which the guidewire tubing is pushed and heldin place when the collet is in a closed position.
 8. The interfaceconnector handle of claim 7, wherein the biasing assembly furthercomprises a spring for forcing the collet toward the closed position. 9.The interface connector handle of claim 7, wherein the biasing assemblyfurther comprises a rubber tube for forcing the collet toward the closedposition.
 10. The interface connector handle of claim 7, wherein thebiasing assembly further comprises a biasing device and a seat which isadjacent to both the biasing device and the collet, the biasing devicebeing for forcing, through the seat, the collet toward the closedposition.
 11. The interface connector handle of claim 7, wherein thebiasing assembly further comprises a biasing device and a connector capthrough which the guidewire tubing is slid toward the female opticalreceiving device, the connector cap capable of movement in a direction,the biasing device exercising a counter force opposite the direction ofmovement of the connector cap, the counter force forcing the collettoward the closed position.
 12. The interface connector handle of claim7, wherein the connector cap is coupled to a protrusion adapted forsliding in a sliding rail, thereby limiting the movement of theconnector cap for defining whether the collet is in the closed positionor not.
 13. The interface connector handle of claim 1, wherein thebiasing assembly comprises a biasing device for urging the proximalportion of the guidewire tubing toward the female optical receivingdevice.